That would probably work, but, my big problem with the fixed mounts is that they are fixed in just two locations. I recently put a Thule cargo box on to factory style cross bars. Not being able to adjust the spacing and location of the cross bars was a show stopper for stability and it also put the box way too far forward into the wind stream. The cargo box is supposed to be installed as far back as possible without getting hit by the rear door when it opens up. I ended up using Yakima Timberline towers and cross bars because they allowed me to set the spacing to hold the Thule box exactly where I wanted it and with the maximum separation to hold it with the most stability.